Fastening means for the stator plates of flywheel magnetos



Nov. 7, 1950 G. F. MCGREVY 2,528,700

FASTENING MEANS FOR THE STATOR PLATES 0E FLYWHEEL MAGNETOS Filed Dec. 8, 1949 2 Sheets-Sheet l In; :.13 I' ,l l 3,1* 2f 6 a vll-. 2 'frana- .I 17 26 i I j 25 1I A! J liz 5 25 INVENToR GEFGE E MC GFL: yy

Nov, 7, 1950 G. F. McGRl-:VY 2,528,700

FASTENING MEANS FOR THE STATOR A PLATES 0F FLYWHEEL MAGNETOS Filed Dec. 8, 1949 v2 Sheets-Sheet 2 lNvENToR Gro/wiz I.' Mc 'Glyzry ATTOR EYS Patented Nov. 7, 1950 UNillD STATES PATENT QFFICE 2,528,700 FASTENING MEA-Ns FOR T HEqsrA'roR PLATES F FLYWHEEL MAGNETOS GeorgeF.. lYicGi'evy, West Springfield, Mass., as-

signor to Wico Electric Company, West Springfield, Mass., aeorpration of Massachusetts Application December 8, 1949, Serial N o. 131,723

Y Clais. l

This invention relates to improved fastening n'ieans for adjustably holding the stator plate of a flywheel magneto on the pilot flange of the crankcase of an internal combustion engine in such a manner that the stator plate may be manually moved to, and frictionally held in, various positions of, angular adjustment on the pilot ilange and retained against axial movement or tilting movement thereon,

The invention is an improvement on that disclosed in Patent No. 2,487,095, granted November 8, 1949, on an invention of Allen L. Brownlee and George F. McGrevy, to the assignee of this invention, Y Y

The invention is desirable for use with the stator plate of a flywheelV magneto, which isto be used on an engine of the variable-spark type, as distinguished from the fixed-spari; type. Such a plate, and the stationary magnetic coil-carrying elements of the magneto mounted thereon, must be movable to various angular positions relative to the engine crankshaft in order to Vary thev timing of the spark produced by the mag'- neto. AnI outboard motor is one eiample of an engine of the type described.

This invention has for an object the provision' of one or more fastening means units for holding the stator plate of a flywheel magneto to a pilot liange on the cra-nlcase of ari internal combustion engine' in various positions o'f angular adjustment, each such unit consisting of a friction shoe, with a spring to press it against the cylindrial surface of the pilot flange, and a spring finger to engage an'inner end face of the pilot flange to yieldingly hold the stator plate against The invention Will be disclosed in one illustrative example with reference'to the accompanying drawings, in which: i

Fig. l is a top plan view of a stator plate for use in a flywheel magnetoA and embodying the fastening means of this'invention,Y a portion of the engine flywheelbeng shown in section;

Fig. 2 is a sectional elevational view of the stator plate taken on the line 2 2 of Fig. 1 and showingalso t'. .-iloi. flange on case and? the engine flywheel;

the engine crank-= Fig. -3 is afragmentary sectional View, taken similarly .to Fig. v2V but showing one unit of the fastening means in an outer position, in which both shoeand linger" are released from engagement with the pilot iiange;` v

Fig. 4 is a fragmentary sectional plaink view taken on the line 4-4 of Fig. 2 and showing the shoe portion of one unit ofthefasteningmeans together with its spring and manual-operating means;

Fig, 5 is a fragmentary bottom plan view of the stator plate showingthe spring ng'er portion of one unit of the `fastening means;

Fig. 6 is arfr'agmentary side elevational View of the stator plate, taken from the right of fi;v

Fig. 7 is a cross sectional View taken on the line'l-'I of Figli; l F 4 Fig. 8 is aview taken similarly to Fig. 7 but with the parts of the fastening means unit removedyand Y 4 V A Fig. Buis aMfragmentary sectional elevational View takenon the line Bll of l.r

Referringv to these4 drawings; the stator plate, as shown in Fig. 1, consists of a circular base I havingan outer marginal rim 2 which projects upwardlyinto a recess (Fig. 2) formed in the lower end face of the rim of the flywheel 3. The typical, cross section of this plate is shown at the right of Fig. 9, such section being modified, as indicated in Fig. 2, where the fastening means, later to be described, are located. The ilywheel (Fig. 2') is 'suitably Xed to the outer end'of the crankshaft@ of an internal combustion'engine. The craiikcase' of the enginesupportsV a stationary pilot `flange 5,7' formed on the outer end of a hub through which the crankshaft fi passes. This pilot flange has a cylindrical surface'4 f5, and outer and inner endA faces l and 8, respectively, which are normalto'the axis ofsurface Ei. The stator l plate l, has' a central recess in its bottom wall crankshaft 4passes.' The stator plate has fixedV thereto, asby screws I, the usual handle shown in part at I2. This handle extends radially out- Wardvbeyond the outer periphery of the flywheel' 3, thence upwardly (Fig, 5) for a distance and nally radially outwardly. In an outboard motor, the stator plate i and flywheel 3 are usually loca-ted in a deep Well which issurrounded by 3 the fuel-supply tank of the motor, and the handle I2 has to pass `upwardly out of this well and thence radially outward above the tank to a position, where it may be conveniently grasped by the operator, as shown for example in the patent, above identified. A

The stator plat I is held ifi place on the described pilot Bange by one Yor more identical units. If the pilot flange is relatively short in axial extent, as illustrated herein, at least two fastening units should be used, as indicated herein in order to prevent the stator plate from tilting to any substantial extent on the pilot flange under the downward pressure or the .upward pull, which may at times be exerted by the operator on the handle I2. If the pilot flange has sufllcient axial length to prevent undue tilting, then a single fastening unit will suffice.

Each fastening unit includes a friction shoe I3 (Figs. 2 and 4) to press on the cylindrical surface 6 of the pilot flange 5 and yieldingly hold the stator plate I in the Various positions of angular adjustment, to which it may be moved by handle I2, and a spring finger I4 (Figs. 2 and 5') to press against the inner end face 8 of the pilot flange and draw the end wall IIJ of the stator plate tightly against the outer end face 'I of the pilot flange. The shoe I3, as shown, is of channel form with inner and outer flanges upstanding from opposite edges of a common base. This shoe and finger are suitably connected together, as by the rivet I5, and are adapted to be moved by the same means in parallel paths in planes normal to the axis of the cylindrical wall 9 toward and away (usually and preferably radially as shown) from such wall. As shown in Fig. 8, the stator plate has a radial groove I6 therein which at its inner end (see also Fig. 4) opens through the wall 9 and at its outer end terminates at the inner face of a lug I1 formed integrally as a portion of flange 2. This groove has vertical side walls I 8 (Fig. 8) spaced to freely receive between them (see Fig. 7) the shoe I3. The groove I6 has a radial slot I9 in its 4bottom wall leaving on each side thereof, flat horizontal surfaces 20, which, as shown in Fig. 7, act as ways to slidably support the shoe I3. The slot I9 communicates at its outer end with a groove 2I in the bottom face of lug I1 (Figs. 2 and 5). Both the slot I9 and groove 2I are of substantially the same width as spring finger I4, the sides of which slidably engage the sides of the slot I9 and groove 2|, whereby the finger is prevented from turning. The outer end of spring finger I4, which rides in groove 2l, bears against the bottom of lug I1. With its outer end thus supported, the spring finger serves yieldingly to hold the shoe I3 against the ways 2U upon which it slides and prevents tilting of the shoe. This is important in order to hold the inner end of nger I4 in proper position so that it will be flexed downwardly and engaged with the inner end face 8. When the finger I4 is engaged beneath end face 8, the shoe I3 is held more firmly to its ways because of the flexing and tensioning of the inner end of the spring. The spring then has its inner end bearing against face 8, its outer end bearing against the bottom of lug I1 and an intermediate portion held by the shoe I 3 bearing on ways 2D. The spring finger serves to close thev slot I9 and prevent the entry of dust and dirt into the space between the stator plate and flywheel, in which the magneto elements are housed, as will later appear.

The means for moving the shoe I3 and spring finger I4 comprise a screw 22 threaded into lug I1 and having on its outer end a hexagonal head 23 with a screw driver slot 24 therein, both ac-l cessible from outside the stator plate. Screw 22 has on its inner end, as an integral part thereof, a coaxial rod 25 of considerably less diameter. The inner end of this rod slides freely through a hole in the outer upstanding part of the channelshaped shoe I3. Encompassing rod 25 is a coil spring 26, which acts between a shoulder on the rod and the outer face of the aforesaid outer part of the shoe I3 to press the latter inwardly against the surface 6 of the pilot flange. Near its inner end and inwardly ybeyond the outer flange of shoe I3, rod 25 is circumferentially grooved to receive a snap washer 21, which acts as an abutment to engage the inner face of said upstanding part, when screw 22 is moved outwardly, in order to draw the shoe outwardly away from the cylindrical surface 6.

When screw 22 is retracted as shown in Fig. 3, the washer 21 will abut the inner face of the outer flange of shoe I3 and move it radially outward on its ways 20, the spring 26 then pressing such flange against the washer. The outside diameter of spring 26 is less than the inside diameter of the screw threaded hole in lug I1 so that on retraction of the screw 22, the spring 26 may enter the threaded hole in lug I1. The arrangement is such that the outer face of the outer flange of shoe I3 can never` be drawn into abutment with the inner face of lug I1 by means of screw 22. The latter will be entirely unscrewed from lug I1 before such faces can be engaged. Thus, the washer 21 cannot be forced off rod 25 by careless operation of screw 22 beyond its neceSsary outward limit of movement. If the screw is by inadvertance entirely unscrewed, the parts of the fastening unit will remain assembled and can again be rendered operative by again threading screw 22 into lug I1. When the screw is threaded into the lug I1, the shoe I3 and finger I4 will move with it until the inner face of the inner flange of the shoe engages the cylindrical surface 6. By that time, the inner end of finger I4 will have moved inwardly beyond the periphery of the pilot flange and into engagement with the inner end face 8 of the pilot flange. As the spring finger I4 moves inwardly and engages such surface, it is deflected and placed under stress to draw and thereafter yieldably hold the end wall of the stator plate against the outer end face 1 of the pilot flange. Continued inward movement of the screw 22 will compress the spring 26 to provide the necessary pressure to yieldingly hold the stator plate against rotation on the pilot flange. Thus, by turning the one member, the screw 22, both the shoe I3 and finger I4 will be moved into active holding positions and the stress of the spring 26 can be adjusted, as required. All this can be accomplished from outside the magneto housing, which is afforded by the flywheel and stator plate. Usually, there is a removable plate in the housing around the engine, which allows access to the outer end of screw 22. Sometimes, the latter can be turned by screw driver inserted in slot 24. cases, the screw can be turned with an open end wrench engaged with head 23.

The invention, being concerned with the fastening of the stator plate on the pilot flange of the engine crankcase, is independent of the construction and arrangement of the magnetic and In other.

lof the pilot flange.

detail: l

These `elements have, however, been indicated in one particular arrangement-in the drawings and'they Awill: be 'briefly described. rIYhe -iiywheeL shownxin part in Fig. Al, carriesapermanent `magnet28with pole shoes-29-connectedlone to each polal` extremity thereof. The `magnet and shoes afrelixedv in the Anen-magneticJ flywheel 3 during the'process of casting -thesamel- In this particu- 'lar case-there -are itwo yidentical Vsets of magnetic elementson the stator. Each set includes a lanfrinatedA iron core structure having-three angularly-spaced'legs `30, -3I and 32, the inner `ends of whiehare magneticallyinterconnectsd and the convex outer-s ends of which are adapted to magnetically connect successively with the concave inner-faces ofthe pole shoes 29. rI?his-core structurelissecured, as by screws `33,.'to suitable Apads such as -34-fon the stator plate. The central leg 3l bearsprimaryand secondary coils 35 and 3E, respectively, herein shown as contained in a molded insulating casing 31, from which emerges a high tension Wire 38, passingout through the `flange 2 of the stator plate, at a level below the flywheel 3,v and adapted for connection to a spark plug of the engine. The breaker mechanism for controlling the circuit of the primary coil 35 includes an arm 39V of insulating material having a breaker point 40 and 'pivoted at 4I to a metallic support 42, fixed to a pad 43 on the stator plate.

vThis support 42 bears the stationary breaker point 44. The breaker arm 39 is actuated from a cam 45, which is fixed on crankshaft 4, by means of a slide, shown in part at 45, and mounted in the pad 43. The usual condenser is shown at 4IWith its insulated terminal connected by a flexible conductor 48 to the breaker point 40. The construction and operation of the magneto is substantially the same as disclosed in the Asstrom and Brownlee Patent No. 2,447.7 27, granted August 24, 1948 to the assignee of the present application.

The stator plate may be quickly and easily mounted on the engine. With each unit of the fastening means withdrawn to a released position, such as shown in Fig. 3, the plate I may be slipped on the pilot flange 5 with its Walls 9 and I0 respectively engaging the surfaces 6 and 1 of the pilot flange. The screws 22 are then turned to move the shoes I3 and lingers I4 radially inward. When the shoes I3 engage the surface 6, the fingers I4 will have been moved into engagement with the inner end face 8 of the pilot iange and placed under stress to yieldingly hold the end Wall I0 in engagement with the outer end face 'i The screws 22 will then be tur-ned farther in the same direction in order to stress the coil springs 26 to the desired degree. The cam 45 is applied to the crankshaft 4 and then the flywheel 3 is fixed to the latter to complete Athe assembly. Whenever the spring pressure on shoes I3 needs adjustment, this may be effected without removing the flywheel 3 from the engine crankshaft, by using a screw driver or wrench, whichever is most convenient in the particular engine involved, applied to the slot 24 or head 23 of Screw 22. The stator plate may easily befremoved from-fthel pilot ange I'-5' a.ft`erf-tl1.`ef-fly` wheel-f3 -ih-as been removed from `the crankshaft 4, by turning =thescrews-22fto move the shoes 1| 3 and #fingers J'I #outwardly to released positionland then :pullingathe plate-axially-off theapilot flange 5. -As previously-fdescribedlthe screws l222'can be completely unscrewed without :causing any1-damage. The lparts of. the.'fastening .unit remainy in assembled relation and cannot Afall .orf the stator plate and' be lost. The-washer 2 'I cannot ybe forced-oilrod 25by unscrewingscrew22.A :Each fastening unit may be replaced. .correctly fsimply bylthreadingsits :screwJ22l into its lug lII.

The location .of :the two fastening units in 'ithe 'mannershown 1in Fig. lis deemed preferable. One unit is .placed `as f closely as pos-sible '.toxhandle AI2/so :that its .ngerwl'll :will byV itsengagement with the innerien'cbface `8 of :thepilotgflangesmost eectivelyresist tilting of vthe `plate I -due :torany upward pull on handle I2.. Thepother.. unit is located-approximately opposite .the4 :handle 12, where its-finger I4L-.can mosteefectively resist tilting .of the plate under downward pressure on the handle. The two: units arezpurposelynot lo,h cated-diametricallyopposite. If. .they were `so ilof cated,-thestator. platesmight easily be .tilted about the-axiscfthe aligned..fricticnshoest Such tilting is prevented by thearrangement shown. The particular pilot. flange l5, :hereinill.ustratedv is threeinches in .diameterandjias an `axial length ot.-three.eighths of..an inch.` With a clearance of .say three .thousandths of anpinch between `the cylindrical .surfaces l'andll,r tilting .of the .stator plate, .to .an ,extent suicient to throw the polar surfacesof legs 30, 3I1and 32 :outof -true coaxial relation `with the pole shoes 29 -o magnet 28, would be possible Aexcept for the vfastening `.means of this invention. To Aresist this tilting, the pilot flange 5 is made relatively large -in diameter to provide a relativelyA large area of engagement of end wall I0 with the outer `end face 7, and substantial spring pressure is applied bythe fingers I4 at two or more points to hold the surfaces 4'I and I0 -in close contact. The degree of. Vtilting possible decreases as the ,axial length of the pilot iiange increases, other factors `being the same. Hence, in installations, where there is roomfor a pilot flange vhaving an axial length great enough to prevent substantial tilting, a single fastening unit may suffice. The number of fastening units is not of the essence of the invention.

The invention thus provides a fastening means for adjustably holding the stator Vplate of a iiywheel magneto on the pilot ange of an engine crankcase in various positions of angular adjust-A ment with respect to the .engine crankshaft and for holding the plate against axial movement on such angeand against tilting thereon, both holding members being movable simultaneously into or out of holding position by a single manually-operable member located outside the magneto housing, such manually-operablemember being movable, after the holding members have been moved Vinto holding position, to adjust the spring pressure of the friction-shoe holding member on the peripheral surface of the pilot flange.

What is claimed is:

l. Fastening means for adjustably holding the stator plate of a ywheel magneto on the pilot angeof an engine crankcase, comprising in combination, a stator plate having a recess with a cylindrical wall, adapted to receive and engage the cylindrical surface of such flange, and an end Wall normal to the axis of the cylindrical Wall and adapted to engage an outer end face of the flange; and fastening means consisting of one or more identical units, eachcomprising -a friction shoe mounted on the inner face of the stator plate for movement toward or away from said cylindrical wall in a path normal to said axis and adapted, when moved inwardly, to press on the cylindrical surface of the pilot ange and frictionally hold the stator plate in various positions of angular adjustment on the flange, a spring linger connected to move with the shoe in a parallel path and adapted, when the shoe is moved inwardly, to engage an inner end face of the pilot flange and draw said end wall against said end face and hold the stator plate against axial and tilting movement on the pilot liange, and manually-operable means accessible from the outer face of said plate for moving the connected shoe and finger in their respective paths between an outer position, in whi-ch the shoe and linger are respectively disengaged from the cylindrical surface and inner end face of the pilot ilange, and an inner position, in which said shoe and linger are respectively engaged with said cylindrical surface and said inner face, said ,f

means including a spring adapted to be stressed by continued operation of such means after said shoe has engaged said cylindrical wall.

2. Fastening means for adjustably holding the stator plate of a flywheel magneto on the pilot flange of an engine crankcase, comprising in combination, a stator plate having a recess w1th a cylindrical wall, adapted to receive and engage the cylindrical surface of such flange, andan end wall normal to the axis of the cylindrical wall and adapted to engage an outer end face of the flange; and fastening means consisting of one or more identical units, each comprising a friction shoe mounted on the inner face of the stator plate for movement toward or away from said cylindrical wall in a path normal to said ax1s and adapted, when moved inwardly, to press on the cylindrical surface of the pilot ilange and frictionally hold the stator plate in various posiy tions of angular adjustment on the ilange, .a spring finger connected to move with the shoe 1n a parallel path and adapted, when the shoe 1s moved inwardly, to engage an inner end face of the pilot flange and draw said end wall against said end face and hold the stator plate against axial and tilting movement on the pilot flange, a screw threaded into the stator plate and having its head located outside the latter, and a spring located between the shoe and screw for transl,

mitting inward movement of the screw to the shoe and connected finger in order to move the shoe to engage said cylindrical surface and the finger to engage said inner end face, said spring being stressed by continued inward movement of the screw after the shoe has engaged said cylindrical surface. Y

3. Fastening means for adjustably holding `the stator plate of a flywheel magneto on the pilot flange of an engine crankcase, comprising in combination, a stator plate .having a recess with a cylindrical wall, adapted to receive and engage the cylindrical surface of such flange, andan end wall normal to the axis of the cylindrical wall and adapted to engage an outer end face of the flange; and fastening means consisting of one or more identical units, each comprising a friction shoe mounted on the inner face of the stator plate for movement toward or away from said cylindricalwall in a path normal to said axis and l I member adapted, when vmoved inwardly, to press on the cylindrical surface of the pilot flangeV and frictionally holdthe stator plate inY various positions of angular adjustment on the ilange,a spring finger connected to move with the shoe in a parallel path and adapted, when the shoe is moved inwardly, to engage an inner end face of the pilot flange and draw said end wall against said end face and hold the stator plate against axial and tilting movement on the pilot flange, a screw threaded into the stator plate and having its head located outside the latter, a spring 1ocated between the shoe and screw for transmitting inward movement of the screw to the shoe and connected finger in order to move the shoe to engage said cylindrical surface and the linger to engage said inner end face, said spring being stressed by continued inward movement of the screw after the shoe has engaged said cylindrical surface, an extension on the screw slidably engaged with the shoe for free inward movement during stressing of said spring, and a shoulder on said extension for abutment with said shoe when the screw is moved outwardly in order to move the shoe and its connected nger outwardly out of engagement with the pilot flange.

4. 1n a stator plate for a flywheel magneto, such plate having a recess with a cylindrical Wall adapted to receive and engage the cylindrical surface of a pilot flange on the crankcase of an internal combustion engine and an end wall normal to the axis of said cylindrical wall and adapted to engage an outer end face of said ange, said plate having an upstanding adjacent its outer periphery and a radially-directed slidevvay between the inner face of said member and the cylindrical surface of the pilotV flange, a screw threaded through said member with its head located outside ythe latter, a rod of less diameter than the screw fixed coaxially of and to the inner end of the screw and extending along and parallel with said slideway, a friction shoe slidably engaged with the slideway and havingr an inner portion t0 engage said cylindrical surface and an outer upstanding part in which the inner end of said rod is slidably engaged, a spring coiled around the rod and located between the outer face of said part and the inner end of the screw, an abutment on the inner end of said rod for engaging the inner face of said part .when the screw is moved outwardly, and a spring finger connected to move with said shoe and adapted to engage an inner end face of the pilot flange when said shoe engages said cylindrical surface to hold said end wall against the outer end face of the pilot ange and prevent axial movement or tilting movement of the stator plate on said ange.

5. ln a stator plate for a flywheel magneto, such plate having a recess with a cylindrical wall, adapted to receive and engage the cylindrical surface of a pilot flange on the crankcase of an internal combustion engine, and an end wall normal to the axis of said cylindrical wall and adapted to engage an outer end face of said flange, said plate having an upstanding member adjacent its outer periphery and a radially-directed slideway between the inner face of said member and the cylindrical surface of the pilot flange, a screw threaded through said member with its head located outside the latter, a rod of less diameter than the screw xcd coaxially 0f and to the inner end of the screw and extending along and parallel with said slidcway, a friction shoe slidably engaged with the slideway and having an inner portion to engage said cylindrical surface and an outer upstanding part in which the inner end of said rod is slidably engaged, a spring coiled around the rod and located between the outer face of said part and the inner end of the screw, an abutment on the inner end of said rod for engaging the inner face of said part when the screw is moved outwardly, said plate having a slot therethrough parallel with and adjacent said slide- Way, a spring finger having an inner end adapted to move into or out of engagement with an inner end face of the pilot flange, said spring nger when its inner end is so engaged filling said slot and closing the same, and a connection between the finger and shoe extending through said slot for moving both the shoe and nger by said screw.

GEORGE F. MCGREVY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

